In Long-Term Evolution (LTE) of Universal Mobile Telecommunication System (UMTS), a physical cell identifier (PCI) consists of a combination of a primary synchronization sequence (PSS) and a secondary synchronization sequence (SSS). The PCIs are divided into modulo 3 groups (PCI mod 3) and modulo 30 groups (PCI mod 30), and the PCI and associated PSS and SSS should be assigned to a cell on the basis of an optimized selection of a PCI mod 3 group and PCI mod 30 group such that reference signal collisions and synchronization signal collisions between neighbouring cells are avoided.